Paracetamol Poisoning in Cats

Paracetamol ( also known as acetaminophen) is a common anti-inflammatory drug found in most supermarkets and household medicine cabinets. It's often use to treat headaches and muscular pain in humans, but it should never be given to an animal, especially cats.

Cats are easily poisoned by paracetamol because they have different liver metabolisms compared to humans. In humans and most other animals, the paracetamol is combined with glucuronide producing a safe product. Cats have very low levels of glucuronide, and consequently more of the paracetamol is processed via the cytochrome P450 pathway, producing the toxic product NAPBQ. NAPBQ damages the red blood cells and liver of cats. Other species, including humans, can also suffer paracetamol poisoning by using a high dose of the drug, or for a long period of time as this will use up the reserved of glucuronide in the liver.

The toxic dose for a cat is 50-100mg of paracetamol per kg of body weight. A large cat may barely survive one tablet without permanent damage. Unfortunately, many unknowing owners who give their cat paracetamol to make it feel better find that after the tablet there is no improvement, and give the cat another. This second tablet guarantees that there is enough paracetamol to cause liver failure and kill the cat.

A cat poisoned by paracetamol may seem nauseous or vomit. They will usually show a Heinz body anaemia and the typical symptoms associated with that: blue or brown gums, lethargy and depression. Cats usually show swollen faces and paws, and may be crying. In severe cases the cat will already be jaundiced and show signs of hepatotoxicity.

Paracetamol poisoning can be treated with timely medical attention, before the liver becomes so badly damaged that it can no longer function. Never administer human medications to animals without consulting your veterinarian. Always read the instructions that come with medications because they are there to prevent you from overdosing. If you are ever in any doubts about your medication seek the knowledgeable help of your doctor or pharmacist

Aspirin is not the same drug as paracetamol, and is generally a safer alternative to administer to animals if it is required in an emergency. It is still important to speak to the vet before doing so, because dose rates will differ between species and it may not be appropriate for your pet.